测量结果与被测量值之间的差叫做（）。
A.零件误差
B.公差
C.系统误差
D.测量误差
参考答案：A
_____ you have mentioned in your speech, Mr. Wang graduated from Beijing University ten years ago. [ ]
A. Which
B. After
C. As
D. Since
农电“反六不”活动内容是什么？
